This Phase II project continues the successful Phase I discovery of novel decorporation agents that are selective for radioactive strontium (Sr). This project consists of the necessary steps for submission of an Emergency Use Authorization (EUA) or Investigational New Drug (IND) application to the US FDA. A goal is to have orally- administered, GI-chelation formulations ready for an FDA application by the end of year for the Strategic National Stockpile (SNS). This project is guided by the Guidance for Industry: Internal Radioactive Contamination -Development of Decorporation Agents. Sr-90 is easily obtained by terrorists;radioactive Sr-decorporation is a very high DHHS / NIH / NIAID / DAIT priority and treatments for Sr-90 exposure remain a critical need for the SNS. Sr-90 and its daughter yttrium-90 are beta emitters that deposit their energy in the body. Sr-90 is readily absorbed by both respiratory and GI routes and up to 50% of a dose will be deposited in bone. Current GI absorption blocking agents, such as aluminum phosphate, are of low effectiveness, although they are recommended for clinical use. There are no Sr-specific decorporation agents available.